From: Cornelia Huck With dma-mapping-prevent-dma-dependent-code-from-linking-on.patch scsi fails to build on !HAS_DMA architectures: drivers/built-in.o(.text+0x20af6): In function `scsi_dma_map': : undefined reference to `dma_map_sg' drivers/built-in.o(.text+0x20b5c): In function `scsi_dma_unmap': : undefined reference to `dma_unmap_sg' I split those functions out into a new file. Builds on s390 and i386. Move scsi_dma_{map,unmap} into scsi_lib_dma.c which is only build if HAS_DMA is set. Signed-off-by: Cornelia Huck Cc: Martin Schwidefsky Cc: Heiko Carstens Cc: James Bottomley Cc: Jeff Garzik Cc: Christoph Hellwig Cc: Dan Williams Signed-off-by: Andrew Morton --- drivers/scsi/Kconfig | 5 +++ drivers/scsi/Makefile | 6 ++-- drivers/scsi/scsi_lib.c | 38 ------------------------- drivers/scsi/scsi_lib_dma.c | 50 ++++++++++++++++++++++++++++++++++ include/scsi/scsi_cmnd.h | 2 + 5 files changed, 60 insertions(+), 41 deletions(-) diff -puN drivers/scsi/Kconfig~scsi-dont-build-scsi_dma_mapunmap-for-has_dma drivers/scsi/Kconfig --- a/drivers/scsi/Kconfig~scsi-dont-build-scsi_dma_mapunmap-for-has_dma +++ a/drivers/scsi/Kconfig @@ -10,6 +10,7 @@ config RAID_ATTRS config SCSI tristate "SCSI device support" depends on BLOCK + select SCSI_DMA if HAS_DMA ---help--- If you want to use a SCSI hard disk, SCSI tape drive, SCSI CD-ROM or any other SCSI device under Linux, say Y and make sure that you know @@ -29,6 +30,10 @@ config SCSI However, do not compile this as a module if your root file system (the one containing the directory /) is located on a SCSI device. +config SCSI_DMA + bool + default n + config SCSI_TGT tristate "SCSI target support" depends on SCSI && EXPERIMENTAL diff -puN drivers/scsi/Makefile~scsi-dont-build-scsi_dma_mapunmap-for-has_dma drivers/scsi/Makefile --- a/drivers/scsi/Makefile~scsi-dont-build-scsi_dma_mapunmap-for-has_dma +++ a/drivers/scsi/Makefile @@ -145,9 +145,9 @@ obj-$(CONFIG_SCSI_DEBUG) += scsi_debug.o obj-$(CONFIG_SCSI_WAIT_SCAN) += scsi_wait_scan.o scsi_mod-y += scsi.o hosts.o scsi_ioctl.o constants.o \ - scsicam.o scsi_error.o scsi_lib.o \ - scsi_scan.o scsi_sysfs.o \ - scsi_devinfo.o + scsicam.o scsi_error.o scsi_lib.o +scsi_mod-$(CONFIG_SCSI_DMA) += scsi_lib_dma.o +scsi_mod-y += scsi_scan.o scsi_sysfs.o scsi_devinfo.o scsi_mod-$(CONFIG_SCSI_NETLINK) += scsi_netlink.o scsi_mod-$(CONFIG_SYSCTL) += scsi_sysctl.o scsi_mod-$(CONFIG_SCSI_PROC_FS) += scsi_proc.o diff -puN drivers/scsi/scsi_lib.c~scsi-dont-build-scsi_dma_mapunmap-for-has_dma drivers/scsi/scsi_lib.c --- a/drivers/scsi/scsi_lib.c~scsi-dont-build-scsi_dma_mapunmap-for-has_dma +++ a/drivers/scsi/scsi_lib.c @@ -2290,41 +2290,3 @@ void scsi_kunmap_atomic_sg(void *virt) kunmap_atomic(virt, KM_BIO_SRC_IRQ); } EXPORT_SYMBOL(scsi_kunmap_atomic_sg); - -/** - * scsi_dma_map - perform DMA mapping against command's sg lists - * @cmd: scsi command - * - * Returns the number of sg lists actually used, zero if the sg lists - * is NULL, or -ENOMEM if the mapping failed. - */ -int scsi_dma_map(struct scsi_cmnd *cmd) -{ - int nseg = 0; - - if (scsi_sg_count(cmd)) { - struct device *dev = cmd->device->host->shost_gendev.parent; - - nseg = dma_map_sg(dev, scsi_sglist(cmd), scsi_sg_count(cmd), - cmd->sc_data_direction); - if (unlikely(!nseg)) - return -ENOMEM; - } - return nseg; -} -EXPORT_SYMBOL(scsi_dma_map); - -/** - * scsi_dma_unmap - unmap command's sg lists mapped by scsi_dma_map - * @cmd: scsi command - */ -void scsi_dma_unmap(struct scsi_cmnd *cmd) -{ - if (scsi_sg_count(cmd)) { - struct device *dev = cmd->device->host->shost_gendev.parent; - - dma_unmap_sg(dev, scsi_sglist(cmd), scsi_sg_count(cmd), - cmd->sc_data_direction); - } -} -EXPORT_SYMBOL(scsi_dma_unmap); diff -puN /dev/null drivers/scsi/scsi_lib_dma.c --- /dev/null +++ a/drivers/scsi/scsi_lib_dma.c @@ -0,0 +1,50 @@ +/* + * SCSI library functions depending on DMA + */ + +#include +#include +#include + +#include +#include +#include +#include + +/** + * scsi_dma_map - perform DMA mapping against command's sg lists + * @cmd: scsi command + * + * Returns the number of sg lists actually used, zero if the sg lists + * is NULL, or -ENOMEM if the mapping failed. + */ +int scsi_dma_map(struct scsi_cmnd *cmd) +{ + int nseg = 0; + + if (scsi_sg_count(cmd)) { + struct device *dev = cmd->device->host->shost_gendev.parent; + + nseg = dma_map_sg(dev, scsi_sglist(cmd), scsi_sg_count(cmd), + cmd->sc_data_direction); + if (unlikely(!nseg)) + return -ENOMEM; + } + return nseg; +} +EXPORT_SYMBOL(scsi_dma_map); + +/** + * scsi_dma_unmap - unmap command's sg lists mapped by scsi_dma_map + * @cmd: scsi command + */ +void scsi_dma_unmap(struct scsi_cmnd *cmd) +{ + if (scsi_sg_count(cmd)) { + struct device *dev = cmd->device->host->shost_gendev.parent; + + dma_unmap_sg(dev, scsi_sglist(cmd), scsi_sg_count(cmd), + cmd->sc_data_direction); + } +} +EXPORT_SYMBOL(scsi_dma_unmap); diff -puN include/scsi/scsi_cmnd.h~scsi-dont-build-scsi_dma_mapunmap-for-has_dma include/scsi/scsi_cmnd.h --- a/include/scsi/scsi_cmnd.h~scsi-dont-build-scsi_dma_mapunmap-for-has_dma +++ a/include/scsi/scsi_cmnd.h @@ -135,8 +135,10 @@ extern void scsi_kunmap_atomic_sg(void * extern struct scatterlist *scsi_alloc_sgtable(struct scsi_cmnd *, gfp_t); extern void scsi_free_sgtable(struct scatterlist *, int); +#ifdef CONFIG_SCSI_DMA extern int scsi_dma_map(struct scsi_cmnd *cmd); extern void scsi_dma_unmap(struct scsi_cmnd *cmd); +#endif #define scsi_sg_count(cmd) ((cmd)->use_sg) #define scsi_sglist(cmd) ((struct scatterlist *)(cmd)->request_buffer) _